How much does an Arabic-English freelance translator charge per word or page of an autobiography?

As with anything else, you get what you pay for. :)

Translation rates for Arabic into English run anywhere from 12 to 18 US cents per Word. You start getting better rates over 5000 Words, so for a book, assuming it is over 25,000 Words your rate will be between 4 and 8 cents. My own rates are right in the middle of those ranges, and I am an ATA certified translator, while 90% of others are not. Louay Abdulla.